CG SCERT (Chhattisgarh Board) Class 8 Science & Technology Solutions | 2026-27 Official Edition
Welcome to the complete, 100% textbook-grounded CG Board Class 8 Science Chapter 17 Solutions: Adolescence (किशोरावस्था) in Bilingual Format (English Medium + हिंदी माध्यम). Every in-text question (Answer these / इनके उत्तर दीजिए) and end-of-chapter exercise (Exercises / अभ्यास के प्रश्न) has been solved strictly from the official 2026-27 SCERT Chhattisgarh Raipur textbook.
End-of-Chapter Exercises (Solutions)
अभ्यास के सभी प्रश्नों के हल
Find out the correct and incorrect sentences Make…
Status Incorrect गलत Correction in English Fathers are…
- (i) Adolescents should be careful about what they eat, because:
- Options:
- A. Proper diet develops their brains.
- B. Proper diet is needed for the rapid growth taking place in their body.
- C. Adolescents feel hungry all the time.
- D. Taste buds are well developed in teenagers.
- Correct Answer: B. Proper diet is needed for the rapid growth taking place in their body.
- (ii) Reproductive age starts when:
- Options:
- A. Menstruation starts.
- B. Breasts start developing.
- C. Body weight increases.
- D. Height increases.
- Correct Answer: A. Menstruation starts.
- (iii) The right meal for adolescents consists of:
- Options:
- A. Chips, noodles, chocolate
- B. Chapatti, dal, vegetables
- C. Rice, noodles and chips
- D. Vegetable, chips and cold drink.
- Correct Answer: B. Chapatti, dal, vegetables
- (iv) Following is male hormone:
- Options:
- A. Testosterone
- B. Estrogens
- C. Insulin
- D. Thyroxin
- Correct Answer: A. Testosterone
(i) Mothers are responsible for the sex of the unborn child.**
- (ii) Children gain height during adolescence.
- (iii) During menstruation girls should not be allowed to work in kitchen.
- (iv) Children in the age group of 13-19 are called infants.
- (v) The zygote with XY chromosome pair develops into a male child.
- (vi) Body of girls becomes unholy during menstruation.
- उत्तर:B. उनके शरीर में हो रही तीव्र वृद्धि के लिए उचित आहार की आवश्यकता होती है।
- उत्तर:A. मासिक धर्म (ऋतुस्राव) प्रारंभ होता है।
- उत्तर:B. रोटी, दाल, सब्जियाँ
- उत्तर:A. टेस्टोस्टेरोन
Explain the followings
किशोरावस्था में लिंग हार्मोन टेस्टोस्टेरोन एवं एस्ट्रोजन के…
- English:
- Mechanism & Chromosomal Structure: Every human cell nucleus contains 23 pairs of chromosomes, including 1 pair of sex chromosomes. Females have XX sex chromosomes and produce ova with only X chromosomes. Males have XY sex chromosomes and produce two types of sperms: 50% carrying an X chromosome and 50% carrying a Y chromosome.
- Fertilisation Outcomes:
- If an X-bearing sperm fertilises the ovum, the resulting zygote is XX, which develops into a female child.
- If a Y-bearing sperm fertilises the ovum, the resulting zygote is XY, which develops into a male child.
- Diagrammatic Flow Explanation:
Mother (XX) × Father (XY)
Egg (X) + Sperm (X) → Zygote (XX) ⇒ Female Child
Egg (X) + Sperm (Y) → Zygote (XY) ⇒ Male Child
- Hindi:
- English:
- Oviparous Animals: Animals that lay eggs covered with a shell, inside which embryonic development occurs outside the mother’s body (e.g., hen, lizard, frog, birds).
- Viviparous Animals: Animals that give birth directly to fully formed young ones after internal development inside the uterus (e.g., human, cow, dog, cat).
- Hindi:
| Age in Years | Boys Height in cm | Girls Height in cm |
|---|---|---|
| 0 | 51 | 51 |
| 4 | 94 | 90 |
| 8 | 112 | 108 |
| 12 | 127 | 131 |
| 16 | 148 | 148 |
| 20 | 171 | 163 |
- Data Table:
- Conclusions drawn from the Graph:
- English:
- At birth (0 years), the average height of both boys and girls is identical (51 cm).
- From age 4 to 8 years, boys grow slightly faster in height than girls.
- Around age 12 years (onset of puberty), girls grow faster than boys and temporarily surpass boys in height (131 cm vs 127 cm).
- By 16 years, both reach the same height, and by 20 years, boys attain a higher maximum height than girls (171 cm vs 163 cm).
- Hindi:
Physical features that appear during puberty under the control of sex hormones (testosterone and estrogen) and help to distinguish males from females are called secondary sexual characters. In boys, facial hair growth (beard and moustache), chest hair, broadening of shoulders, and deepening of voice occur. In girls, development of breasts, enlargement of mammary glands, and widening of the pelvic area take place.
Speech Report on the Legal Status Illeffects of…
कानूनी स्थिति भारत में विवाह की कानूनी आयु…
Legal Status: In India, the legal age for marriage is 18 years for girls and 21 years for boys**.
- Two-Minute Speech Content: “Respected Teacher and Friends, child marriage is a severe social evil. Adolescents under the legal age are neither physically nor mentally mature for marriage and responsibilities of motherhood. Early pregnancy leads to high health risks, anemia, maternal mortality, and infant malnutrition. Furthermore, child marriage deprives young boys and girls of education and personal growth. We must completely eradicate child marriage to ensure a healthy society.”
Article on HIVAIDS Awareness
एचआईवीएड्स क्या है एड्स AIDS एक घातक संक्रामक…
What is HIV/AIDS?** AIDS (Acquired Immuno Deficiency Syndrome) is a dangerous viral disease caused by HIV (Human Immunodeficiency Virus).
- Modes of Transmission:
- Sharing infected syringes or needles during drug intake.
- Unprotected sexual contact with an infected person.
- Transmission from an infected mother to her infant through breast milk or pregnancy.
- Prevention: Always use sterile disposable syringes, avoid drug abuse, test blood before transfusion, and raise public awareness.
Sex Ratio Concerns Gender Equality
ति 1000 पुरुषों पर 882 महिलाओं का अनुपात…
A census ratio of 882 females per 1000 males indicates a alarming decline in female population due to social discrimination and female foeticide. Community concerns highlight that boys and girls possess equal potential to achieve excellence. Eliminating gender bias and encouraging girl education is essential for balanced societal progress.
Importance of Knowing Facts About Reproduction
जनन के वैज्ञानिक तथ्यों की सही जानकारी किशोरों…
Understanding correct scientific facts about human reproduction empowers adolescents to discard myths and superstitions (such as blaming mothers for child sex or treating menstruation as unholy). It enables youth to maintain personal health, practice hygiene, say ‘No’ to drugs, and make responsible decisions regarding reproductive health and family planning.